I have the lens over a year, and can only write that it is excellent maps, well finished and hardly something better is at least for Canon housing with APS-C sensor on the market that Aperture 2.8 has and about the same zoom range. The lenses of Fremherstellern with approximately the same technical data can not keep up. These are less expensive but as far as the overall performance of the Canon still the best and unfortunately also the most expensive. The only weakness was the dust susceptibility. Apparently that's not the case with every model but in my Also the dust accumulated under the front lens. In the pictures, this is not visible but it does not forgive for that price. Since the front lens is removed quite quickly with 3 screws and thus the dust can be removed within 10 minutes I give anyway 5 points. Finally, the sensor of the cameras has also so once a year clean that's part of it. In my copy, it is sufficient to carry out this cleaning once a year. You can also do anything wrong, the front lens is removed only briefly, suck up dust with a vacuum cleaner and lens it screws back in the same position, that was it already. It is not a secret that one should wait until the warranty expired. During the warranty period, you can free the lens when Canon to clean customer service.
